Posted by Short Axplaination on May 09, 2002 at 20:01:16:
In Reply to: Re: Short action posted by Doug again on May 09, 2002 at 19:33:34:
Just as the tubing enters the valve section, it is changed from round to oval. The volume remains approximately (hopefully) the same. With "squished" oval holes in the pistons, the defined stoke is shorter.
Once the air column leaves the valve section, it is converted back from oval to round.